Thanks for the info.

I wonder if there's any LED that runs on the receiver ports. I think I saw them somewhere before but I just can't remember where. The higher voltage options are certainly going to work but that would require some modification to the existing wires.

I can't recall just where it is mentioned in the rules, but power lights are supposed to be wired across the main power lines. Its possible for a LED on the receiver to be off if its power source is broken, but for other parts of the bot to still be powered up and potentially dangerous.
_________________
Australian 2015 Featherweight champion
UK 2016 Gladiator champion

I believe its only suggested here to do that, but still a good idea
_________________
www.demon50s.com - Minimoto parts
http://www.youtube.com/user/HyzerGlen - Videoooozzz

"8.6. All Robots must have a light easily visible from the outside of the robot that shows its main power is activated."

Main power is usually interpreted to mean the battery voltage after any switches or links.

Thank you, guys. I will try to combine a few LEDs in serial and use them as a power light then.

Update:

Just did the second weapon test with one motor, this time with one of the capacitors flying off the ESC! Yay!

I actually performed two tests. The first spin-up was all right, and the spinner stopped about 30 seconds after when I left off the throttle. However, in the middle of the second test I heard a pop sound after I left off the throttle. The spinner still stopped just fine, but when I got closer I found the capacitor about 5cm in front of the ESC. The ECS and motor seemed just fine in terms of temperature. Even the capacitor in question seemed fine other than the fact that the pins broke off from the solder.

I wonder why the ESC failed during a spin-down, with braking function off (took pretty long to spin down, and neither the ESC and motor felt hot).

Video and pics coming soon.

What I have been doing for power LEDs recently is buying self-adhesive LED strips from HobbyKing. These are only a few bucks. You can cut them to length and they have built-in resistors so you can run them straight off a 3s or 4s LiPo.

If you want to use other (low current) LEDs, all you really need is a resistor in series with it. It's different if you want to use some 10W monster LED that can light up a whole room. But for normal LEDs just a resistor will do.

Not sure how electrically minded you are but if you need a hand choosing resistor values let me know.

Thanks, that will be great. I'm running 6s lipo... So what LED and resistor combo should I use?

If you use LED strips, they come in 12V and 24V versions with resistors already built in. For the 12V strips, just run two sections in series.

If you want to use a single LED, find a large , bright one and then use an on-line LED calculator to find the right value resistor - there are dozens to choose from. Its impossible to specify the right resistor without knowing the current draw and forward voltage of the LED, so the calculator is the way to go.

You can use any colour or size but not a flashing LED and preferably one that is bright enough to be seen with the strong arena lighting
_________________
Australian 2015 Featherweight champion
UK 2016 Gladiator champion

After further checking, I found that the drive ESC (used purely as a BEC in the test) has a hole on its heatshrink. Not sure if that was me soldering like a noob a few weeks ago or actually caused by today's test. (The capacitor sure is blown off by today's test, see my earlier post.)

Here are a few pictures showing the damage taken.





Testing video:
https://www.youtube.com/watch?v=ARZuYFWqTuc&feature=youtu.be

Thanks Nick, I guess I will just go buy some from Jcar then.

Its hard to know exactly what went wrong from the photos - its probably not a power overload or all the FETs would have died and there would be more damage. having overheated parts and a capacitor blown off could be related to the BEC not handling 22V or maybe the ESC was just very poor quality. A close-up photo with the heathrink off the ESC might help ID what section of the ESC had the fault.

BTW: that test set-up is really dangerous - if the bot vibrated off the box, the disk could hit the floor and cause absolute chaos. Better to do it at floor level and maybe with a weight on the back to keep the bot steady.

Apart from the ESC dying, the test is very promising
_________________
Australian 2015 Featherweight champion
UK 2016 Gladiator champion

Thanks for the advice, I will keep future testings on the ground.

Here's a photo without the heatshrink:
The other cap is gone too... It only has one lead remaining. Also where the pins broke off there seemed to be some burning.

People on Facebook are saying that I have to go get bigger capacitors...

With the Nationals just around the corner where can I find these capacitors quick? (Checked JayCar, their caps are either too small or too big.)

Looking good so far.

The caps popped probably from having the battery wires too long, inductance and ripple will kill them really fast. Its better to have long motor wires and the battery ones short otherwise pile on lots of the biggest capacitors you are able to on the battery leads.
_________________
www.demon50s.com - Minimoto parts
http://www.youtube.com/user/HyzerGlen - Videoooozzz